Plastic pollution is recognized as one of the most urgent global environmental concerns. China is the top producer and consumer of plastics and creates the most plastic waste globally. To evaluate policy options to control plastic pollution in China, we first reviewed the relevant policies and action plans in place. Then, we examined plastic-material flows and changes at the national level based on officially published data to evaluate the current situation and efficacy of policies at the macro-level. Results showed that 2016, the start of the 13th Five-Year Plan, was a pivotal year in the history of China’s plastic policies tackling plastic issues nationally and internationally. Since 2016, the growth trend in the production and consumption of plastic products has slowed and the recycling rate has risen, surpassing 30% in 2021. To further tackle plastic pollution, key suggestions with important policy implications were provided, covering better integration of policies, the combined management of vertical–horizontal governance, tracking-system implementation, the introduction of a quality-certification system, the development of behaviour-based consumer-oriented solutions, the promotion of stakeholder collaboration, and the need for appropriate post-COVID-19 policies.

The crisis ignited by COVID-19 has transformed the volume and composition of waste generation and requires a dynamic response from policy makers. This study selected Bangkok as a case study to semi-quantitatively examine the impact of the COVID-19 outbreak on consumer-generated food and plastic waste by examining changes in lifestyles and consumption behaviour through a face-to-face questionnaire survey. Travel bans and diminished economic activity due to COVID-19 have led to a dramatic reduction in waste from the business sector and in the total amount of municipal waste generated. However, the results of the survey showed that both food and plastic waste generated by households in Bangkok increased during COVID-19. The shift from eating out to online food delivery services led to an increase in plastic bags, hot-and-cold food bags, plastic food containers, and food waste. Reasons for the increase in household food waste during COVID-19 varied, with respondents citing excessive amounts of food and unappetising taste, followed by exceeding the expiration date and rotting/foul odours. These reasons may be the result of the inability to predict quantity and quality when ordering online, and inadequate food planning and management by consumers. To achieve more effective food and plastic waste management, home delivery services, consumer food planning and management, and the formation of a circular economy based on localised supply chains may be considered as important intervention points.

Due to its ability to recover both material and energy from organic waste, biogas technology is considered one of the best technology for treating organic waste. While in many emerging Asian countries more than 50% of municipal waste is organic waste, the amount of organic waste treated with biogas technology remains very limited. This study identified key challenges faced by practitioners in sustaining biogas plants from literature and interviewed a number of sustainably operating biogas plant managers and, based on the findings, developed an implementation framework to help decision makers and practitioners in planning a sustainable municipal organic waste biogas plant facility.

The issue of food waste, especially in developing economies, is a puzzle. Hanoi was selected as a case study to examine the current situation of food waste generated by consumers through daily habits/practices and to evaluate options for preventing and reducing food waste at the policy level through a literature/policy review and interview-style survey. An analysis of responses found that the self-reported food waste generation rate in Hanoi averaged 1192 g/day/household in urban areas and 1694 g/day/household in rural areas; cooking waste generated during meal processing/preparation accounts for more than 70% of the total; less than 20% of respondents separated out kitchen waste for reuse/recycling before disposal; expiration dates and deteriorating quality were cited as primary reasons for food waste at home in contrast with larger portions and over-ordering outside the home; leftover food is used indirectly as animal feed in urban areas and directly in rural areas; and most respondents indicate a willingness to reduce, reuse, and recycle food waste. To achieve SDG target 12.3, policymakers and practitioners must develop comprehensive food waste policies and actions targeting the entire supply chain, implement practical food waste management systems, and promote sufficiency strategies for saving food, reducing food waste, and maintaining health and well-being.